Future distributed systems will support continuous media such as digital audio and video, allowing user programs to convert, process, store, and communicate continuous-media data. The DASH project is developing such a system. Our work consists of two related parts. First, we have defined the DASH resource model as a basis for reserving and scheduling resources (disk, CPU, network, etc.) involved in end-to-end handling of continuous-media data. The model uses primitives that express workload characteristics and performance requirements, and defines an algorithm for negotiated reservation of distributed resources. This algorithm is embodied IP+, a backwards-compatible extension of the Internet Protocol(IP).
Second, we have developed a distributed system kernel for use as an experimental testbed. The DASH kernel implements the DASH resource model for scheduling of CPU and network access. Its virtual memory system provides efficient data transfer between address spaces. Finally, its implementation is structured using object-oriented programming and message-passing.